Pond Boss Forums POND CONSTRUCTION Soil questions Lining a pond with 6 mm plastic or similar

I'm new to pond building and thinking, but I am wondering about this idea. It's just a thought, but it's been bugging me so I figured I might as well ask.

No doubt a lot of factors play into this, but after you've dug your pond and set aside some clay would it help to line your pond with 6 mm plastic vapour barrier plastic (or similar/heavier or even multiple layers)? You could then hand spread the clay over or use light machinery once you've laid down your plastic. You'd get some holes in the liner from running over it and stones poking through, but it would surely help reduce seepage? I'm sure it would work best on a smaller scale pond since you'd have to hand spread most of the clay overtop, or perhaps there was a better way to finish it that I haven't thought of? Regardless plastic is cheap and it doesn't have to be seemless since you're just trying to reduce seepage to some degree. My plan would call for 6"-12" of clay ontop of the plastic, but it could just be dirt since ultimately it would be the plastic being the best barrier.


Has anyone tried this or have any thoughts on it? Is there anything I haven't thought of that plastic might make things worse or unfeasible?

Great forum btw!

Hello Billert and welcome to Pond Boss. Wow we are seeing quite a few Canadian pond meisters sign up lately. I'll let the pond guru's answer your question. This is a fantastic site and don't hesitate to post any and all questions. We're glad you found us.

(NOTE: JHAP, you are always shaming me into taking a stab at these things. )

(2nd NOTE: Which then gives actual experts something to correct. )

Billert, I bet you would have to put some holes in the plastic (causing some more water loss, in addition to that from the seams), to prevent whalebacking (gases rsing from below the pond, becoming trapped under the plastic, and eventually floating it up).

If there was enough clay to put a 12" layer above the plastic, I'd just try to scrounge up another 12" worth, if possible, and compact it real good. Then I wouldn't need the plastic.

This is an art that I have carefully developed over many, many years. You should see some of the stuff I've conned DIED into doing.

Of course then again he made me eat Brussel Sprouts so I guess it goes both ways.

You need to stop in Ahia the next time you go to PA. You ever had possum innards?

Nope. Do they wrap them in bacon?

Yep. Beef bacon, even.

Good call on the gases idea. I guess the spacing would depend on how much gas you had huh? lol

I would think the plastic would essentially last forever though. Hmmmm.

Hey billert; good to have ya postin'!
I have to be the bad cop on this one. I don't want you to get your hopes up and start makin' plans. I recall a thread within the last year or so about this same thing, and I thought the idea got fairly well trashed.
Personally, if I was digging a pond small enough that I could afford the experiment, then I would just do the right thing and put in a correct liner. If I was digging a pond large enough that I couldn't afford a bad decision, I would dismiss vapor barrier as a liner and use conventional methods.
BTW, all this comes from Mr unconventional risk taker, willing to spend $100 to save 50. Also, stay clear of Theo's possum innards until Sunil samples one of his possum innard sticks.

What are acceptable alternative as liners aside from clay bottoms?

I can sorta see how a lot of things could go wrong with the plastic since it's essentially impermiable. It might work better on the sides since gas wouldn't be an issue, but then the dirt wouldn't exactly stick well to it and tend to slide down to the bottom again.

An experiment indeed.

First off, what makes you think you even need one? Are you familiar enough with your soils (at the depth of the proposed basin) to know that a liner is a potential necessity?
Secondly, how big of a pond are we talkin'?

Or try the freshly pickled crabgrass or hard boiled nails.
http://www.frickers.com/menu/pdf/carryout_2007.pdf

I thought Rooster's had possum and racoon on their menu...farm raised too!

Call Bend Tarp and Liner. I shopped around alot! They have a thin liner that is very cost efective and very very tough. I had clean dirt with a few small pebbles. Your soil will determine if you can use the thin stuff. I tested a piece of it by running it over with a bobcat before I ordered. It will be roughly about the same cost as the plastic you talk about. My liner was 165ft by 295ft. Came in one piece and was worth every penny. I put about a foot of dirt on top of it. Its now full and looks great. I fought leaks for a long time.

Great story nashfisherman

You also need to consider the type of plastic. Most types of plastics are not made for use with fish and can bleed toxic chemicals into the water over time as is the case with Polyethylene.
The heavier plastics are more expensive but as with (Firestone EDPM) come with a 20 year warranty against UV degradation. I have used this several times and it lasts long and doesn't puncture easily. Covering it with soil though would mean slower tapered shorelines or the soil would tend to erode and slip down the plastic.
Barry

Covering the lner will cost a little more, but that is the only way to go.